A "Doc Holliday Cough" is the unsettling, abrupt and ill-sounding cough produced by an ostensibly healthy individual. Doc Holliday, the sharp shooting associate of Dodge City lawman Wyatt Earp, was known to have terminal tuberculosis and in film is often portrayed as being wracked by fits of coughing.

A "Doc Holliday Cough" is a cough that, without any other evidence or observation, imparts a sense of illness or poor health.

The girl who sat next to me on the bus had a Doc Holliday cough so I made sure to wash my hands a lot and change my clothes when I got home.